To calculate the payback period on an equipment purchase, divide the full installed cost by the net cash the equipment adds each month, and the formula tells you how many months it takes to earn its price back. A loan, a down payment and the tax write-off each change what that answer means. This guide runs cash and financed examples and shows how to line payback up against a loan term so you can judge whether financing makes sense.
What is the payback period formula for an equipment purchase?
The simple payback formula used in capital budgeting is:
Payback period = initial investment / net cash inflow per period
The initial investment is everything it takes to get the equipment running: price, freight, installation, training and any sales tax, minus trade-in value or the sale price of the machine it replaces. The net cash inflow is the extra cash the equipment produces, from new work, labor saved or outsourcing you stop paying for, minus what it costs to run.
When cash flow is even, one division does it. When it ramps up, add cash flow period by period until the running total covers the cost. With assumed figures for a $120,000 machine:
| Year | Net cash flow (assumed) | Running total | Still to recover |
|---|---|---|---|
| 1 | $40,000 | $40,000 | $80,000 |
| 2 | $60,000 | $100,000 | $20,000 |
| 3 | $60,000 | $160,000 | Recovered |
Payback lands in year three: two full years plus $20,000 / $60,000 = 0.33 of a year, or about 2.3 years (28 months).
Payback ignores the time value of money and any cash earned after the cost is recovered, so on its own it can't tell you which machine is the better long-term buy. A discounted payback discounts each year's cash flow first, which lengthens the result. For a financing decision, simple payback in months is still the handiest number, because it lines up directly with a loan term.
Working out the monthly cash flow the equipment adds
Most payback mistakes happen on the cash flow side, because the price comes from a quote while the benefits are estimates. Build the monthly figure line by line:
- New gross profit: revenue from added work minus materials and other direct costs. Counting revenue alone makes payback look faster than it will be.
- Costs avoided: subcontracting or rental fees, overtime, repairs and downtime on the old machine.
- Running costs: operator wages, maintenance, insurance, fuel or power, consumables and software.
- Ramp-up time: months before output reaches your assumed level, which matters if payments start right away.
For the examples below, assume a $120,000 machine (installed) that adds $6,500 a month in gross profit and $1,500 a month in running costs, for $5,000 a month in net pre-tax cash flow. These figures are illustrations, and they aren't benchmarks for any industry.
A cash purchase example, before and after the tax write-off
Paying cash, simple payback is $120,000 / $5,000 = 24 months.
Taxes touch both sides of that division: the new profit is taxable, and the purchase may be deductible. As of October 6, 2026, IRS Publication 946 says that for tax years beginning in 2026 the maximum section 179 expense deduction is $2,560,000, reduced by the amount by which the cost of section 179 property placed in service during the tax year exceeds $4,090,000. It also describes a 100% special depreciation allowance for certain qualified property acquired and placed in service after January 19, 2025, with an election to take 40% instead for the first tax year ending after that date, and the IRS calls the 100% deduction permanent (IR-2026-06, January 14, 2026). Section 179 has a business income limit too, so whether you can use the full write-off in year one depends on your income. See our Section 179 guide and confirm the details with your tax adviser.
Now assume a 25% combined tax rate (an assumption that depends on your entity and income) and a full first-year write-off worth $30,000:
| Method | Investment | Monthly cash flow | Payback |
|---|---|---|---|
| Pre-tax | $120,000 | $5,000 | 24 months |
| Shortcut: after-tax cost, pre-tax cash flow | $90,000 | $5,000 | 18 months |
| Consistent after-tax | $90,000 | $3,750 | 24 months |
The shortcut row is the one to avoid. It takes the $30,000 saving off the price but still divides by pre-tax cash flow, counting the tax benefit while ignoring the tax on the new profit. Done consistently, a full first-year write-off at a steady tax rate leaves payback about where the pre-tax math put it. The saving also arrives when you file or lower your estimated payments, while the seller wants paying at delivery.
When the write-off is spread over several years, after-tax payback gets longer. In Canada, the Canada Revenue Agency's capital cost allowance page (modified August 31, 2026) says you cannot deduct the full cost of depreciable property in the year you acquired it, and you claim a yearly capital cost allowance instead, at rates that depend on the property's class. Finance Canada has since proposed immediate expensing for most depreciable property acquired on or after September 15, 2026, so check its status and run the after-tax version with your accountant.
How does financing change the payback period?
Financing doesn't change what the machine earns. It changes when you pay for it and adds interest. Take the same machine with a 10% down payment ($12,000) and $108,000 financed at an assumed 9% fixed rate. Real rates vary by lender, credit and equipment, as our equipment financing rates guide explains. Cash flow stays at $5,000 a month, pre-tax:
| Loan term | Monthly payment | Cash left each month | Cash flow / payment | Total interest | Payback including interest |
|---|---|---|---|---|---|
| 24 months | $4,934 | $66 | 1.01x | $10,415 | 26.1 months |
| 36 months | $3,434 | $1,566 | 1.46x | $15,637 | 27.1 months |
| 48 months | $2,688 | $2,312 | 1.86x | $21,004 | 28.2 months |
| 60 months | $2,242 | $2,758 | 2.23x | $26,514 | 29.3 months |
| 84 months | $1,738 | $3,262 | 2.88x | $37,960 | 31.6 months |
The last column divides the price plus total interest by $5,000, the time needed to earn back everything you'll pay. On the 60-month loan, the $12,000 down payment comes back in about 4.4 months ($12,000 / $2,758).
The 24-month row shows the key relationship. Cash flow is roughly cost divided by payback, and the payment is roughly the amount financed divided by the term, plus interest. So the equipment covers its own payment only when payback is shorter than the term. Here the down payment and the interest nearly cancel out, leaving $66 a month.
Longer terms buy breathing room at a price: the 84-month loan carries about $22,300 more interest than the 36-month loan.
▦Estimate your equipment paymentRun the numbers in the equipment financing estimator →▸How long should payback be to justify financing?
No official rule sets a target payback period for equipment, and lenders apply their own credit standards. Our view is that two tests matter more than any single number: payback should sit comfortably inside the loan term, and well inside the equipment's useful life. A machine that pays back in 24 months on a 60-month loan covers its payment about twice over and leaves years of cash after the loan ends.
| Payback compared with the loan term | What it means each month | How we'd read it |
|---|---|---|
| Well under the term (24 vs 60 months) | Equipment cash flow covers the payment about 2x | Financing usually holds up, if the cash flow estimate is sound |
| Close to the term | Payment absorbs nearly all the new cash | Thin margin, so consider a longer term, a bigger down payment or a cheaper machine |
| Longer than the term | Payment exceeds what the equipment produces | The purchase leans on other income, so rework the numbers |
| Longer than the useful life | The equipment never earns back its cost | Don't buy on these assumptions |
Then stress-test the estimate. If cash flow comes in 25% below plan ($3,750 a month), the 60-month payment still leaves $1,508, the 36-month payment leaves $316, and the 24-month payment runs $1,184 short every month.
Lenders run their own version of this test, often through debt service coverage, which compares the cash your whole business has available for debt payments with all of those payments. Requirements vary by lender and program, and our DSCR guide walks through the math.
SBA loans and longer terms for long-lived equipment
For equipment with a long useful life, an SBA-backed loan can stretch the term and widen the monthly cushion. As of October 6, 2026, SBA's 7(a) loan page lists purchasing and installing machinery and equipment as an eligible use, with a maximum loan amount of $5 million, and its 7(a) terms and conditions page says maturity is ten years or less unless the loan finances or refinances real estate or equipment with a useful life exceeding ten years. The 504 loan program covers long-term machinery and equipment with a useful remaining life of a minimum of 10 years and offers 10-, 20- and 25-year maturity terms.
A long term can make a slow payback look affordable, but the equipment has to keep earning well past its payback point, and you'll pay more interest along the way. Match the term to the useful life and compare total interest across terms.
Through EQ Funding, one application reaches equipment financing and SBA lenders who compete for your deal, so you can compare offers with different terms and run each one through the payback math above. Lenders set approval, rates and terms based on your credit and repayment ability.